Reproducer mounting



Oct. 27, 1925- 1,558,847

I c. J. DELJMARMOL REPRODUCER MOUNTING Filed Nov. 25, 1923 PB cwzwmezzw Patented Oct. 27, 1925.

CHARLES J. DELMARMOL, or PHILADELPHIA, PENnsYLvAnIA.

REPRODUCER MOUNTING.

Application filed November 23, 1923.

To all 2071 am may; conccm:

Be it known that I, CHAuLns J. DELMAR- Mon, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented new and useful Improvements in a Reproducer Mounting, of which the following is a specification. 7

My invention relates to new and useful improvements in a reproducer mounting for use with sound reproducing and sound recording machines and has for its primary object to simplify and improve the construction of the supporting mechanism up on which the stylus bar is mounted to 0s cillate in transmitting vibrations to and from the diaphragm through said stylus bar.

Another object of this invention is to provide'a single spring of unique shape for yieldingly connecting the stylus bar supporting plate with a rigid supporting men'r ber such as a reproducer or a bearing plate, the latter adapted to be secured to the re producer.

A further object of my invention is to produce a stylus bar supporting mechanism comprising a supporting plate carrying bearing pins to impinge against a surface of a rigid member and an s-shaped spring connected centrally thereof with the rigid member and having its ends acting upon the supporting plate at diagonally opposite points.

A still. further object of my invention is to arrange the different elements so that the bearing pins and spring fastening means will all be in the longitudinal center of the stylus bar supporting plate while the stylus bar and spring fastening means will be in the transverse center of said supporting plate and the stylus holder is offset from both centers.

ther objects of the invention are to provide cushions between the ends of the spring and stylus bar supporting plate and to interpose a shock absorbing device between said supporting plate and an associated rigid element.

The advantages of my invention include the production of a highly sensitive suspension mechanism for'the stylus bar so that the quality of the sound reproduced will be improved particularly by the elimination or reduction of extraneous noises; the facil- Serial No. 676,488.

ity with which the parts may be assembled because of the use of a single spring which is secured in place at a single point, and a more even distribution of the tension on the supporting plate due to the use of said single spring because the temper of a single spring is more accurate or even than that of two separate springs as generally used at the present time.

lVith these ends in View, this invention consists in the details of construction and combination of elements hereinafter set forth and then specifically designated by the claims.

In order that those skilled in the art to which this invention appertains, may understand how to make and use the same, I will describe its construction in detail, referring by numerals to the accompanying drawing forming a part of this application, in which Fig. 1, is a back face view of a reproducer showing my improvement applied thereto.

Fig. 2, is an end View of the mounting or stylus bar supporting mechanism removed from the reproducer.

Fig. 3, is a bottom plan View thereof.

Fig. 4, is a face view of the S-shaped spring.

Fig. 5, is an enlarged longitudinal sectional View of the supporting mechanism with a portion of stylus bar broken away.

Fig. -6, is a transverse section thereof.

Fig. 7, is a face view of the supporting plate illustrating the location and arrangement of the different elements.

Fig. 8, is an enlarged end View of the supporting mechanism showing a slight modification and a part of the stylus bar broken off.

In carrying out my invention as here embodied, 10 represents a reproduce'r which may be of any desirable or preferred construction and in which is mounted in any approved manner the usual diaphragm 11.

To this diaphragm is fastened the upper end of the stylus bar 12 the lower end of which is suitably secured in the stylus bar supporting plate 13. The supporting plate has a hole 14- located Within both the longitudinal and transverse centers of the plate. two other holes 1515 in the longitudinal center of the plate in line with the hole M one of said holes 15 being adjacent eachend of said plate. Another hole 16 in the trans vers center of the plate adjacent one side edge thereof or offset from the longitudinal center, and also a hole 17 offset from both centers of the plate and therefore closer to one end and side edge than to the other edges of said plate, all of which is apparent by inspection of Fig. 7

The supporting plate 13 carries bearing pins 18 one adjacent each end of said plate in the longitudinal center thereof and are preferably set in the holes 15. These pins are pointed as indicated at 19 for contact with a fixed supporting member represented by the rigid plate 20 or the surface of the reprodncer casing and although not absolutely essential it has been found advisable to set the points of the pins 18 in detents 21 in the rigid or fixed supporting member. Such an arrangement permits the stylus bar supporting plate 13 to freely oscillate or vibrate.

To hold the supporting plate 13 in place I provide an S-shape'd spring or tension member 22, the ends of which act upon the supporting plate at two diagonally opposite points, as at two of the corners of said plate. the ends of said spring preferably having compressible pads 23 of some suitable material, such as rubber interposed between them and the outer face of the supporting plate 13 to which said pads may be fixed as by an adhesive. A screw 24 passes through the center of the spring 22 and has threaded connection with the supporting member 20, said screw passing through the hole 1 1 in the supporting plate and has a bushing 25 surrounding it with one end en gaging the supporting member 20 and the other end engaging the spring 22, the said bushing being of sufficient length to project some distance beyond the outer face of the supporting plate 13 with its outer end terminating short of the outer faces of the compressible pads 23 so that when the screw 21 is driven home the center portion of the spring will be bowed inward to provide the proper or desired tension on the outer free ends of the spring. The spring 22 being fastened only at one point it is desirable to provide means other than said fastening device to prevent accidental displacement or rotation of the spring and in order to accomplish this I prefer to bend the extremities of the spring arms inward so as to form lips 26 Fig. 6, that will engage the edges of the compressible pads and maintain the spring in its proper place.

Depending from the stylus bar support-- ing plate 13 is the stylus holder 27 of any desirable or well known construction and this stylus holder is fixed to the supporting plate in a position offset from both the, longitudinal and transverse centers thereof and is mounted in the hole 17 provided for this purpose. By thus positioning the stylus holder the weight of the reproducer may be greatly reduced as the center of gravity is such that little weight is required to properly maintain the stylus in contact with the record. It being possible to make the reproducer of much lighter weight all unnecessary drag is eliminated and the quality and depth of the sound tones will be greatly imp ro ve-d.

lVhcre the bearing pins 18 impinge upon a surface provided by the reproducer casing the entire supporting mechanism is attached thereto by the single screw 2 1 but where a plate 20 is provided the main elements of the supporting mechanism are secured to said plate by means of the screw 24 and this plate in turn is attached to the reproducer casing by means of other suitable fastening memhere such as the screws 28 which latterpass through the plate 20 and are threaded into the reproducer casing.

In practice the vibrations transmitted to the supporting plate 13 will cause the same to freely oscillate because of the two needle bearing points of the pins 18 on the rigid supporting men'iber 20 and due to the long yielding arms of the spring or tension member thereby making the device exceedingly sensitive so that the complete pitch, force and quality of the sounds may be recorded or reproduced with definiteness and continuity.

The construction above described also completely obviates the chatter or rattle of the supporting mechanism but in order to further guard against the possibility of any undue movement of the parts a shock absorber 29 may be provided which consists of a piece of wire shaped to provide a coil 30 with arms 31 projecting therefrom and inserted in suitable holes in the side edges of the stylus bar supporting plate 13 and the rigid supporting member such as the plate 20. This shock absorber which is in fact a wire spring is set to normally hold the supporting plate 13 parallel with the supporting member so as to act in both directions according to the vibrations of the plate 13.

In Fig. 8, I have shown a slight modification wherein the compressible pads 23 are eliminated and the ends or arms of the spring 22 bent upward or inward to form arcuate bearing toes 32 for direct contact with the underside of the stylus bar supporting plate 13.

As will be seen by reference to Fig. 3, the stylus holder 27 is located in one of the crotches of the S-spring so as not to interfere with the action of the latter in any way.

Of course I do not wish to be limited to the exact details of construction as herein shown as these may be varied within the limits of the appended claims without departing from the spirit of my invention.

Having thus fully described my invention, What I claim as new and useful is 1. In a reproducer mounting, the combination of a rigid supporting member, a stylus bar supporting plate, pins carried by the latter and bearing against the former, a spring having its ends positioned for action upon the supporting plate at diagonally opposite locations, means to support the center of said spring from the supporting member, and a stylus bar and stylus holder carried by the supporting plate.

2. A stylus bar supporting mechanism comprising, in combination, a supporting element, an S-shaped spring suspended centrally from the supporting element, and a stylus bar supporting plate interposed between the spring and supporting element with the .ends of the spring acting thereon and said plate having bearing means to en game the supporting element.

3. The combination With a stylus bar supporting mechanism including a supporting element, a plate disposed parallel With the supporting element, bearing means carried by the plate and engaging the support- .ing element and a spring suspended from the supporting element and acting upon the plate, of a shock absorber comprising a resilient coil and arms projecting therefrom, said arms being connected with the sup )orting element and plate.

4. In a reproducer mounting, the combination of a rigid supporting member, a plate disposed beneath said member, bearing pins carried by the plate and having sharpened ends to engage the supporting member, a screw passing through the plate and threaded into the supporting member, a bushing surrounding said screw and projecting belOW the plate, an S-shaped spring mounted centrally on said screw and engaging the bushing, the ends of said spring being bent to form arcuate bearing toes to engage the outer face of the plate, and a stylus bar carried by the plate.

5. In a device of the character stated, a plate, a spring, means for supporting said spring, said means passing through the plate at the meeting point of the longitudinal and transverse centers of said plate, the ends or said spring acting on the plate at diagonally opposite points, one on each side of the longitudinal center of the plate, a pin at each end of the plate and in the longitudinal center thereof to bear against a surface, a stylus bar carried by the plate and located in the transverse center of said plate to one side of the longitudinal center, and a stylus holder carried by the plate and located on the other side of the longitudinal center of said plate and to one side of the transverse center thereof.

6. The herein described combination of a fixed member having detents therein, a plate carrying bearing means registering With said detents, means acting as a hanger depending from the member and passing through the plate, and a yieldable member held in place by the hanger means and having its ends acting upon the plate at diagonally opposite points.

In testimony whereof, I have hereunto atfixed my signature.

CHARLES J. DELMARMOL. 

